llama-swap.go: remove debounce, replace fmt.Printlns (#731)

small fixes to clean up the main(): 

- remove the debounced config reload 
- replace fmt.Println with a proxy.LogMonitor for consistency

llama-swap.go

@@ -4,12 +4,12 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"log"
 	"net/http"
 	"os"
 	"os/signal"
 	"path/filepath"
-	"runtime"
+	"strings"
+	"sync"
 	"syscall"
 	"time"
 
@@ -34,24 +34,40 @@ func main() {
 	keyFile := flag.String("tls-key-file", "", "TLS key file")
 	showVersion := flag.Bool("version", false, "show version of build")
 	watchConfig := flag.Bool("watch-config", false, "Automatically reload config file on change")
+	mainLogger := proxy.NewLogMonitor()
 
 	flag.Parse() // Parse the command-line flags
 
 	if *showVersion {
-		fmt.Printf("version: %s (%s), built at %s\n", version, commit, date)
+		fmt.Printf("version: %s (%s), built at %s", version, commit, date)
 		os.Exit(0)
 	}
 
 	conf, err := config.LoadConfig(*configPath)
 	if err != nil {
-		fmt.Printf("Error loading config: %v\n", err)
+		mainLogger.Errorf("Error loading config: %", err)
 		os.Exit(1)
 	}
 
 	if len(conf.Profiles) > 0 {
-		fmt.Println("WARNING: Profile functionality has been removed in favor of Groups. See the README for more information.")
+		mainLogger.Warn("Profile functionality has been removed in favor of Groups. See the README for more information.")
 	}
 
+	switch strings.ToLower(strings.TrimSpace(conf.LogLevel)) {
+	case "debug":
+		mainLogger.SetLogLevel(proxy.LevelDebug)
+	case "info":
+		mainLogger.SetLogLevel(proxy.LevelInfo)
+	case "warn":
+		mainLogger.SetLogLevel(proxy.LevelWarn)
+	case "error":
+		mainLogger.SetLogLevel(proxy.LevelError)
+	default:
+		mainLogger.SetLogLevel(proxy.LevelInfo)
+	}
+
+	mainLogger.Debugf("PID: %d", os.Getpid())
+
 	if mode := os.Getenv("GIN_MODE"); mode != "" {
 		gin.SetMode(mode)
 	} else {
@@ -78,15 +94,7 @@ func main() {
 	// Setup channels for server management
 	exitChan := make(chan struct{})
 	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
-
-	// Reload signals (SIGHUP on POSIX, none on Windows — Windows does not
-	// deliver SIGHUP). Always wired up so `kill -HUP` works regardless of
-	// --watch-config.
-	reloadChan := make(chan os.Signal, 1)
-	if runtime.GOOS != "windows" {
-		signal.Notify(reloadChan, syscall.SIGHUP)
-	}
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
 
 	// Context that bounds the lifetime of background watcher goroutines.
 	watcherCtx, watcherCancel := context.WithCancel(context.Background())
@@ -97,20 +105,36 @@ func main() {
 	}
 
 	// Support for watching config and reloading when it changes
+	reloading := false
+	var reloadMutex sync.Mutex
 	reloadProxyManager := func() {
+		reloadMutex.Lock()
+		if reloading {
+			reloadMutex.Unlock()
+			return
+		}
+		reloading = true
+		reloadMutex.Unlock()
+		defer func() {
+			reloadMutex.Lock()
+			reloading = false
+			reloadMutex.Unlock()
+		}()
+
+		mainLogger.Info("Reloading Configuration")
 		if currentPM, ok := srv.Handler.(*proxy.ProxyManager); ok {
 			conf, err = config.LoadConfig(*configPath)
 			if err != nil {
-				fmt.Printf("Warning, unable to reload configuration: %v\n", err)
+				mainLogger.Warnf("Unable to reload configuration: %v", err)
 				return
 			}
 
-			fmt.Println("Configuration Changed")
+			mainLogger.Debug("Configuration Changed")
 			currentPM.Shutdown()
 			newPM := proxy.New(conf)
 			newPM.SetVersion(date, commit, version)
 			srv.Handler = newPM
-			fmt.Println("Configuration Reloaded")
+			mainLogger.Debug("Configuration Reloaded")
 
 			// wait a few seconds and tell any UI to reload
 			time.AfterFunc(3*time.Second, func() {
@@ -121,7 +145,7 @@ func main() {
 		} else {
 			conf, err = config.LoadConfig(*configPath)
 			if err != nil {
-				fmt.Printf("Error, unable to load configuration: %v\n", err)
+				mainLogger.Errorf("Unable to load configuration: %v", err)
 				os.Exit(1)
 			}
 			newPM := proxy.New(conf)
@@ -132,94 +156,72 @@ func main() {
 
 	// load the initial proxy manager
 	reloadProxyManager()
-	debouncedReload := debounce(time.Second, reloadProxyManager)
-
-	// Listen for ConfigFileChangedEvent unconditionally so SIGHUP and the
-	// poll-based watcher both feed the same debounced reload pipeline. The
-	// UI also listens for the matching ReloadingStateEnd emitted from
-	// reloadProxyManager.
-	defer event.On(func(e proxy.ConfigFileChangedEvent) {
-		if e.ReloadingState == proxy.ReloadingStateStart {
-			debouncedReload()
-		}
-	})()
-
-	// SIGHUP (or platform-equivalent) → reload. Back-to-back signals collapse
-	// to one reload via the debounce window, which is the desired behavior.
-	go func() {
-		for range reloadChan {
-			fmt.Println("Received reload signal, reloading configuration")
-			event.Emit(proxy.ConfigFileChangedEvent{
-				ReloadingState: proxy.ReloadingStateStart,
-			})
-		}
-	}()
 
 	if *watchConfig {
 		go func() {
 			absConfigPath, err := filepath.Abs(*configPath)
 			if err != nil {
-				fmt.Printf("Error getting absolute path for watching config file: %v\n", err)
+				mainLogger.Errorf("watch-config unable to determine absolute path for watching config file: %v", err)
 				return
 			}
-			fmt.Println("Watching configuration for changes (poll-based, 2s interval)")
+			mainLogger.Info("Watching configuration for changes (poll-based, 2s interval)")
 			(&configwatcher.Watcher{
 				Path:     absConfigPath,
 				Interval: configwatcher.DefaultInterval,
 				OnChange: func() {
-					event.Emit(proxy.ConfigFileChangedEvent{
-						ReloadingState: proxy.ReloadingStateStart,
-					})
+					reloadProxyManager()
 				},
 			}).Run(watcherCtx)
 		}()
 	}
 
-	// shutdown on signal
+	// Signal handling
 	go func() {
-		sig := <-sigChan
-		fmt.Printf("Received signal %v, shutting down...\n", sig)
-		watcherCancel()
-		ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-		defer cancel()
+		for {
+			sig := <-sigChan
+			switch sig {
+			case syscall.SIGHUP:
+				mainLogger.Debug("Received SIGHUP")
+				reloadProxyManager()
+			case syscall.SIGINT, syscall.SIGTERM:
+				mainLogger.Debugf("Received signal %v, shutting down...", sig)
+				watcherCancel()
+				ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+				defer cancel()
 
-		if pm, ok := srv.Handler.(*proxy.ProxyManager); ok {
-			pm.Shutdown()
-		} else {
-			fmt.Println("srv.Handler is not of type *proxy.ProxyManager")
-		}
+				if pm, ok := srv.Handler.(*proxy.ProxyManager); ok {
+					pm.Shutdown()
+				} else {
+					mainLogger.Error("srv.Handler is not of type *proxy.ProxyManager")
+				}
 
-		if err := srv.Shutdown(ctx); err != nil {
-			fmt.Printf("Server shutdown error: %v\n", err)
+				if err := srv.Shutdown(ctx); err != nil {
+					mainLogger.Errorf("Server shutdown: %v", err)
+				}
+				close(exitChan)
+				return
+			default:
+				// do nothing on other signals
+			}
 		}
-		close(exitChan)
 	}()
 
 	// Start server
 	go func() {
 		var err error
 		if useTLS {
-			fmt.Printf("llama-swap listening with TLS on https://%s\n", *listenStr)
+			mainLogger.Infof("llama-swap listening with TLS on https://%s", *listenStr)
 			err = srv.ListenAndServeTLS(*certFile, *keyFile)
 		} else {
-			fmt.Printf("llama-swap listening on http://%s\n", *listenStr)
+			mainLogger.Infof("llama-swap listening on http://%s", *listenStr)
 			err = srv.ListenAndServe()
 		}
 		if err != nil && err != http.ErrServerClosed {
-			log.Fatalf("Fatal server error: %v\n", err)
+			mainLogger.Errorf("Fatal server error: %v", err)
+			os.Exit(1)
 		}
 	}()
 
 	// Wait for exit signal
 	<-exitChan
 }
-
-func debounce(interval time.Duration, f func()) func() {
-	var timer *time.Timer
-	return func() {
-		if timer != nil {
-			timer.Stop()
-		}
-		timer = time.AfterFunc(interval, f)
-	}
-}